1. Field of the Invention
The present invention relates to a backup module for a standard memory chip, more especially a standard memory chip (for example, DIP, QFJ and PLCC packages) having high-density pins for the backup of a personal computer. If the standard memory chip is out of order, the backup module according to the present invention can take the place of the standard memory chip. By switching between two or more chips, the capacity of the memory can be effectively increased as a whole and the content (program or data) of the memory can be easily optimized.
2. Description of the Related Art
A general high-density-pin type of memory chip (for example, DIP, QFJ and PLCC packages) is mounted on a base board in plane. For achieving the purpose of backup or increasing the capacity, the mounting of an additional chip would result in the increase of area occupied by the chip so that the whole area of a base board layout is increased and the manufacture cost is increased accordingly. On the other hand, there is a solution by a cubic arrangement. However, a conventional cubic arrangement is designed for special purpose and can not be used widely. Also, the manufacture for cubic arrangement is very complex and the manufacture cost can not be lowered.
In prior art, there is used a memory chip of small sized package for decreasing the area occupied by the chip so that the capacity can be increased. However, the backup chip is not a standard package chip, and the maintain cost would be increased. Since the backup chip is not a standard package chip, the manufacture cost is increased and the usage thereof can not be freely changed. For the user who does not need the backup function, the cost is increased unnecessarily.
There is a conventional system in which the data in memory can be changed. However, when the writing of data is defective, the system has a problem that it can not be started up. Under the circumstance, it is necessary for the maintainer to pull out the chip by detaching the whole system and to rewrite the data in memory by an expensive special memory writer. In addition to the expensive cost, the user needs to spend a lot of time.
For system software engineers who develop BIOS (basic input/output system), it is necessary to prepare a computer system for developing BIOS, a developed computer system for using BIOS and an apparatus for rewriting the content of memory chip. Therefore, the cost is very expensive.
If the source memory chip is arranged at the upper part for discriminating signals from a base board, the base board needs to be designed as having two layers of circuits, In this case, the total height of the base board would be increased excessively and a problem is occurred that an interference between each component is produced.
Up to now, there are two types of standard memories, one type is of rectangular shape (DIP package) and the other type is of square shape (QFJ and PLCC packages). With respect to a rectangular memory, please refer to FIG. 1A showing a situation where a source memory 109 is mounted on a memory socket 111 provided on a base board 110 before a memory module having backup function is used, FIG. 18 shows a prior art memory module having backup function which can be inserted in a memory socket 111 provided on a base board 110, wherein the memory module comprises a first conductor part 101 which can be inserted in the memory socket 111, a first base board 102, a second conductor part 103 which can be connected to a second base board 106, a backup memory 104, a chip (not shown), a third conductor part 105 which can be connected to the first base board 102, a second base board 106 and a memory socket 107. In the case shown in FIG. 18, it is necessary to use two base boards. Therefore, the total height of a memory module having backup function will be increased significantly. Also, the manufacture cost Thereof is very expensive. If the prior art memory module having backup function is designed as having only one single base board as shown in FIG. 1C, the memory module will occupy an area larger than the source memory does. Under the circumstance, the mounting operation of the memory module will be interfered with some other components, and it is necessary to redesign the mother board (printed circuit board).
As to a square memory, please refer to FIG. 2A showing a situation where a source memory 209 is mounted on a memory socket 211 provided on a base board 210 before a memory module having backup function is used. FIG. 2B shows a prior art memory module having backup function which can be inserted in a memory socket 211 provided on a base board 210, wherein the memory module corprises a support part 202, a first conductor part 201, a first base board 203, a chip 204, a backup memory 205, a second conductor part 206, a second base board 207 and a memory socket 208 in which a source memory 209 can be inserted, In the prior art memory module having backup function shown in FIG. 2B, since the chip 204 is mounted beside the backup memory 205, the memory module will occupy an area larger than the source memory does. Therefore, the mounting operation of the memory module will be interfered with some other components, and it is necessary to redesign the mother board (printed circuit board). The detailed structure of the first conductor part 201 and the support part 202 is shown in FIG. 20 The total height of the first conductor part 201 and the support part 202 would be height h1 plus height h2. Accordingly, the total height of the memory module will be increased unnecessarily. Also, the strength of the first conductor part 201 is very week. This would induce a phenomenon that the first conductor part 201 will be bent over after a long-period use.
An object of the present invention is to provide a memory module having backup function, comprising: a memory connector having a plurality of pins, adapted to be connected to a memory socket; a backup memory having capacity equivalent to that of a source memory, connected to a main system through a plurality of pins of the memory connector; a switching means for selecting a backup memory or a source memory; and a memory socket for inserting a source memory.
In the memory module having backup function according to Embodiment 1 of the present invention, the control pins of the memory connector are lead out from a portion near the control pins of the source memory and are not contacted with the control pins of the source memory.
In the memory module having backup function according to Embodiment 1 of She present invention, the through hole for the control pin of the memory connector and the through hole for the control pin of the source memory are as near as possible.
In the memory module having backup function according to Embodiment 1 of the present invention, an insulator is provided between the control pin of the memory connector and the control pin of the source memory.
Another object of the present invention is to provide a memory module having backup function, characterized by comprising: a memory connector consisting of an inner support part and a lead part, the inner support part having a configuration substantially equivalent to that of a source memory, a hollow chip mounting part being provided in the inner support part for mounting a specific chip, the lead part being adapted to be connected to an original memory socket for connecting with the base board of a backup system; a switching means, for selecting a backup memory or a source memory; a backup memory having capacity equivalent to that of the source memory, connected between the switching means and the main system through the pins of the memory connector; a memory socket for inserting a source memory, connected to the main system through the switching means; and a base board on which a specific chip is mounted, having two or more layers of circuits, one layer of circuit being connected to the memory connector, and the other layer of circuit being connected to the backup memory and the memory socket.
In the memory module having backup function according to Embodiment 2 of the present invention, the inner support part of the memory connector is made of an insulator having on outer configuration similar to the inner configuration of the original memory socket; a plurality of grooves are provided at the periphery of the inner support part; the conductor part is made of a plurality of conductor posts which are adapted to be inserted into the grooves; and the width and height of the conductor posts are slightly more than those of the inner support part.
In the memory module having backup function according to Embodiment 2 of the present invention, the cross section of the grooves provided at the periphery of the inner support part is flask-shaped; the shape of the conductor posts corresponds to that of the grooves; and both ends of the conductor posts are wider than the middle of the conductor posts.
In the memory module having backup function according to Embodiment 2 of the present invention, the specific chip is consisted of a plurality of chips.
In the memory module having backup function according to the present invention, the backup memory can be used to expand memory capacity.
In the memory module having backup function according to the present invention, the backup memory is a DRAM.
In the memory module having backup function according to the present invention, the backup memory is a SRAM.
In the memory module having backup function according to the present invention, the backup memory is a flash ROM.
In the memory module having backup function according to the present invention, the backup memory is a programable semiconductor chip.
In the memory module having backup function according to the present invention, the switching means is manual.
In the memory module having backup function according to the present invention, the switching means is automatically turned on and off based on the determination of an electrical signal.
With the above structure, an optimistic conductivity can be obtained and the manufacture cost of a memory connector can be reduced. In the memory module having backup function according to the present invention, the signal connection through the memory connector is reliable and stabile.
With the above structure, the connection between the insulator and the conductor is tight Therefore, the conductor will not be moved due to an external force or heat, and the signal transmission in the memory module having backup function according to the present invention is stabile.
When a DRAM is used as a backup memory, BIOS can be easily reset and the manufacture cost can be reduced. When a SRAM is used as a backup memory, BIOS can be fast and easily reset. When a flash ROM is used as a backup memory, user needs not to worry a suddenly shutdown of power. When a programmable semiconductor chip is used as a backup memory, a PAL programmable chip can be replaced and tested for developing a system.
When the switching means is manual, a switch can be provided externally for switching the backup memory and source memory at low cost When the switching means is designed as an automatic switch, the switching between the backup memory and source memory can be achieved based on the determination of an electrical signal.